Radiation Oncology/Ear Cancer

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• Very rare, only about 300 people in the United States diagnosed each year

• Types of ear cancer:

(1) Skin cancers: basal cell carcinoma, squamous cell carcinoma, melanoma, etc.

(2) Adenoid cystic carcinoma: account for only 5 percent of cancers of the external auditory canal

(3) Parotid tumors

• Often starts as a skin cancer on the outer ear that then spreads throughout the various ear structures, including the ear canal and the eardrum

• Can affect the bone inside the ear called the temporal bone (also including the mastoid bone)

• Tumors of the auricle most often treated with limited surgery, with definitive radiotherapy reserved for anatomy preservation or in poor surgical candidates

• Radical surgery (temporal bone resection and mastoidectomy) and postoperative irradiation accepted for more advanced lesions of the external auditory canal and lesions in the middle ear and mastoid

• Tumors involving the auricle can be treated with electrons or with superficial/orthovoltage irradiation:

(1) Lesions involving the pinna must be treated with conventional fractionation (1.8 to 2.0 Gy daily) to prevent cartilage necrosis (doses of 66 Gy over 6.5 weeks recommended)

(2) Large lesions of the external auditory canal may be treated with irradiation alone or combined with surgery (IMRT can improve target coverage and when nodal coverage indicated, doses of 60 to 70 Gy over 6 to 7 weeks required)